The American National Standards Institute (ANSI) has developed cartridges with standard dimensions for holding recording media. In that manner the manufacturers of cartridges and the manufacturers of recording/playback apparatus (drives) have the capability of developing their respective products for use with a variety of other manufacturers products. The standard cartridge includes datum features, for example, locating holes, that are designed to mate with datum features in a drive, for example locating pins, to accurately position the cartridge within the drive. Holding features in the cartridge such as notches and recesses, are dimensioned relative to the datum features. After insertion of a cartridge into a drive, the notches are typically used to hold the cartridge while it is loaded onto the drive spindle and simultaneously loaded onto the locating pins.
The front and side edges of the standard cartridge are held to a tight tolerance relative to the locating holes, the datum features of the cartridge, whereas holding features for example, notches and recesses, located in the sides of the cartridge, are less tightly toleranced. For that reason wear of the locating holes and cartridge hub occur during loading as the cartridge is moved onto the locating pins. The inventors herein have developed an apparatus design for holding the cartridge before and during the loading operation by means of locating pins inserted into the locating holes as well as using the locating pins and holes to position the cartridge within the drive after loading is accomplished.
The inventors herein have sought to repeatedly position and hold the cartridge in a manner which minimizes wear on the locating holes as well as on the hub within the cartridge upon which the media is mounted. In that manner, the life of the cartridge, that is the number of loads which the cartridge can withstand before wearing out, is substantially increased.
In the prior art, holding of the cartridge within the drive is typically accomplished before the loading operation by mating holding notches in the exterior case of the cartridge with corresponding features in the inside surfaces of a holding tray or sleeve. Thus, holding and positioning of the cartridge is accomplished prior to the motion to load the cartridge into a mating relationship with the spindle. Such a design may inaccurately position the locating holes of the cartridge relative to the locating pins and the hub of the cartridge and the spindle relative to each other, dependent on tolerances in the cartridge case, the holding tray, the tray bushings, and the base plate. As a result, the loading operation may forcibly reposition the cartridge on the locating pins and the spindle thus wearing the hub and the locating holes and may result in jamming the load mechanism.
The inventors herein have sought to eliminate this buildup of tolerances and have developed apparatus to accomplish the elimination of tolerances associated with the tray, loader arms, drive plate, base casting and spindle motor. Also, by accurately positioning the cartridge relative to the locating pins before lowering the cartridge, wear on the hole is minimized. Finally, by accurately positioning the cartridge before loading it on the spindle, wear on the cartridge hub is minimized.